Method for improving physical properties of clays and clay-containing soils and compositions resulting therefrom



United States Patent ()flice 3,132,960 Patented May 12, 1964 3,132,960 IWETHOD FOR Ill/IPROVING PHYSICAL PROPER- TIES OF CLAYS AND CLAY-CONTAINING SOILS AND CQMPUSITIONS RESULTING THEREFROM John B. Hernwall, Long Beach, Calif., assignor to The Dow Chemical Company, Midland, Mich, a corporation of Delaware No Drawing. Filed May 3, 1961., Ser. No. 107,325 29 Claims. (Cl. 106287) This invention concerns compositions and methods for the treatment of clays and clay-containing soils having at least weight percent clay, dry basis, with a substituted 2H-l,3-benzoxazine (hereafter S-2H-1,3-BO) having the formula:

in which R is one of alkyl containing 1 to 18 carbon atoms and cycloalkyl containing 6 to 12 carbon atoms; R is one of H, alkyl containing 1 to 12 carbon atoms and cyclohexyl; and R is one of H, alkyl containing 1 to 12 carbon atoms and cyclohexyl. The invention particularly concerns treating clays and clayey soils for the controlled fracturing of crust-forming soils in agriculture.

Clays and clay-containing soils are widespread, occurring naturally in various geological deposits. They have the properties of being dimensionally unstable and of forming fluid cohesive and adhesive mixtures in the presence of water. Conversely, upon drying, they become extremely stress resistant. While many of the uses of clays and clayey soils depend upon these properties, they are a distinct handicap in agriculture. Thus, clay-containing soils which have been exposed to rain or irrigation water and subsequently dried often will form crusts through which plant penetration is very difficult or impossible.

For agricultural purposes, it is impossible to avoid the use of a clay containing soil where it exists, except to retire it from agricultural production. Frequently, however, the crusting problem with such soils is mitigated by the use of crops which are more capable of penetrating through crusts, or by planting several seeds together so that by their combined effort at least one plant will emerge, or by transplanting seedings, in which case the plant does not need to penetrate the crusted soil surface. In many cases these are quite satisfactory solutions to the crusting problem. In other cases, however, these techniques impose restrictions on the growerlhat he would prefer to avoid. The other alternative used, of course, is to proceed in the hope that the conditions necessary to crust formation do not occur before the plants have penetrated the soil surface. While this is frequentlythe case, there are numerous times when it is not, and severe losses to the farmer result. Thus, there is a definite need for clays and clayey soils, which, after natural or artificial watering and then drying, have the property of less stress 6-methyl-3- (2-cyclohexylcyclohexyl) -3,4-dihydro-2H- resistance than such soils or materials when'untreated.

Such treated clayey soils can be considered to be less water sensitive than thecorresponding untreated soils.

This invention is particularly concerned with the treatment of clays and clay c ontaining soils having at least 5 weight percent, dry basis, of a naturally occurring clay, e.g., of the kaolinitic, montmorillonitic, illitic or mixed layer type, with a S-2H-1,3-BO compound, as specified above, in an amount ranging between about 00025 and 2 weight percent, dry clay basis, to improve their physical properties for agricultural purposes.

By way of illustration, the following sorts of S-2H-1,3- BO compounds can be used in the practice of this invention:

6-cyclohexyl-3,4-dihydro-3- (3 ,5 ,5 -trimethylhexyl) -2H- 1,3-benzoxazine 6-cyclohexyl-3-dodecyl-3,4-dihydro-2H-1,3-benzoxazine 3,6-didodecyl-3,4-dihydro-2H-1,3-benzoxazine 3-heXadecyl-3,4-dihydro-2H-1,3-benzoxazine 6-methyl-3-hexadecyl-3,4-dihydro-2H-1,3-dihydro-2H-1,

3-benzoxazine 3,4-dihydro-3-octadecyl-2H-1,3-benzoxazine 6-( l, 1 -dimethylpropyl) -3 -cyclohexyl-3,4-dihydro-2H- l 3-benzoxazine 6-nonyl-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine 6-dodecyl-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine 6-methyl-3-cyclohexyl-3,4-dihydro-2H-1,S-benzoxazine 6-isopropyl-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine 6,8-di-sec-butyl-3-cyclohexyl-3,4-dihydro-2H-1,3-

benzoxazine 6-pentyl-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine 6-( l, l-dimethylbutyl) -3-cyclohexyl-3,4-dihydro-2H- 1,3-benzoxazine 6-sec-heXyl-3-cyclohexy1-3,4-dihydro-2H-1,3-benzoxazine 6-( l-ethyl-l-methylpropyl) -3-cyclohexyl-3,4-dihydro-2H- 1,3-benzoxazine 6-( l-ethyll-methylbutyl) -3 -cyclohexyl3,4-dihydro-2H- 1,3-benzoxazine 6-(1-ethyll-methylpentyl) -3-cycloheXyl-3,4-dihydro-2H- 1,3-benzoxazine 6-sec-buty1-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine 6-( l-methylbutyl)-3-eyclohexyl-3,4-dihydro-2H-1,3-

benzoxazine 6-tert-butyl-3,4-dihydro-3-methyl-2H1,3-benzoxazine 6-tert-butyl-3-butyl-3,4-dihydro-2H-1,3-benzoxazine 6-tert-butyl-3-allyl-3,4-dihydro-2H-1,3-benzoxazine 6-methyl-3-hexyl-3,4-dihydro-2H-1,3-benzoxazine 6-( 1, l-dimethylpropyl) -3 hexyl-3,4-dihydro-2H-1,3-

benzoxazine 6-( 1, l-dimethylpropyl) -3- 1,3-dimethylbutyl) -3,4-dihydro-2H-1,3-benzoxazine 1,3-benzoXazine 6-tert-butyl-3 (2-cyclohexylcyclohexyl) -3 ,4-dihydro-2H- 1,3-benzoxazine 6-(1,1-dimethylpropyl)-3-(Z-cyclohxylcyclohexyl)-3,4-

- 6-tert-butyl-3 ,4-dihydro-3- (Z-methylcyclohexyl -2H-1, 3-

benzoxazine 6-cyclohexyl-3,4-dihydro-3-propyl-2H-1,3-benzoxazine 6-cyclohexyl-3-hexyl-3,4-dihydro-2H-1,3-benzoxazine 6-cycloheXyl-3,4-dihydro-3-octyl-2H-1,3-benz0xazine 3 They may be prepared following procedures disclosed in U.S. Patent 2,806,031.

The S-2H-1,3-BO compounds can be applied to the clay or clay-containing soil in several ways. The preferred way involves dispersing the S-ZH lB-BO compound either as a suspension or as a solution in a liquid medium and admixing the resulting liquid dispersion with the clay or clay-containing soil via spraying, slurrying or other suitable methods. Suitable liquids for dispersion have a boiling point up to ca.150 C. and include water, ketones, alcohols and hydrocarbon solvents, mixtures thereof and emulsions thereof, either oil-in-water or water-in-oil.

Because of the diverse nature of the S-2H-1,3-BO compound utilized in the practice of this invention, some types of compounds are soluble, dispersible or emulsifiable in relatively hydrophilic media, others in relatively hydrophobic media. Upon inspection of a chemical formula, the art skilled can generally determine a solvent, dispersion medium or emulsifier satisfactory for a given S-ZH- 1,3-BO compound. In any event, the operability and desirability of a given solvent, dispersion medium or emulsifying agent can be determined by a simple test wherein a given S-2H-1,3-BO compound is dissolved, suspended or its solution emulsified in a given medium. Obviously, solvents, diluents and emulsifying agents are used which are inert toward the S-2H-1,3-BO compound. Hereinafter, such solutions, suspensions and emulsions will sometimes be referred to broadly as dispersions and the solvent, suspension and emulsion media will be referred to broadly as dispersion media. Advantageously, the S-2i-I1,3-BO compound dispersion contains between 0.0025 and 50 weight percent of S-2H-1,3-BO compound.

The treatment of the clay or clay-containing soil with the S-2H-1,3BO compound should result in the clay or clay-containing soil containing at least 0.0025% and advantageously up to 2% by weight of the S-2H-1,3-BO compound, dry clay basis. The upper limit is essentially economic. The S-Z H-lfi-BO compounds used for agricultural purposes need be applied only to the actual volume of soil treated. Thus, when a S-2H-1,3-BO compound is used to decrease soil crusting, it is practical to treat only the soil immediately above the seed row. Depending upon how carefully the S-2H-1,3-BO compound is applied to this restricted volume of soil, anywhere from 0.1 pound to pounds of the S-2H-l,3-BO compound is sulficient to treat one acre of crop land.

The modulus of rupture (MR) is a test to determine the maximum stress that a material will withstand without breaking and is determined by subjecting a rectangular briquette to a bending moment. This test is commonly accepted by soil scientists as a measure of the crusting potential of a soil and, hence, its relative suitability as an agricultural soil.- The lower the maximum stress before rupture, the less the crusting potential of the soil.

The MR was determined herein on an apparatus patterned after that as described and used by LA. Richards in theSoil Science Society of America Proceedings, 17:

In each set of determinations conducted to provide the data for the following examples, one control was included. The control was prepared in a manner exactly analogously to the other treatments except that no S-2H-1,3-BO compound was used.

The following examples describe completely specific embodiments and the best mode contemplated by the inventor for carrying out his invention. They are not to be construed as limiting the invention, which is defined in the claims.

EXAMPLE 1 A series of samples of finely ground, air-dried, slightly acid, clay loam soil was brought up to a moisture content of about 17% by spraying water as a. fine mist onto the soil samples while subjecting them to thorough mixing. Various S-2H-1,3 BO compounds, as indicated in follow- 4 ing Table I, were immediately added in series to the soil samples by spraying with and mixing in 5 to 10 ml. of an acetone solution containing 20 mg. of the S-2H-1,3-BO compound per g. of air-dried soil to provide a treated soil containing 200 ppm. of S-2H-1,3-BO compound on a dry soil weight basis.

Once the soil had been treated, it was allowed to stand in the open air for at least two hours and then was dried in an oven at 30 C. overnight. The heated soil was then divided into replicates of 25 to 30 g. each and placed into two rectangular molds 3.2 cm. wide by 6.4 cm. long. The soil in the molds was then leveled and compacted with a special compacting tool. The compacting tool has a base which covers the leveled soil sample and onto which was dropped a weight of 31.5 g. from a height of 31.5 cm. This weight was dropped repeatedly for six times, after which the soil was flooded with water. After the excess water had drained through the soil, the samples were dried overnight in an oven at 30 C. The resulting briquettes were then tested by the method cited above for their MR.

Table I S2H-1,3-BO compound: MR in millibars Control 2350 6-cyclohexyl-3,4-dihydro 3 (3,5,5-trimethylhexyl)-2H-1,3-benzoxazine 400 6-cycloheXyl-3-dodecyl 3,4 dihydro-2H-1,3- benzoxazine 1175 3,6-didodecyl 3,4 dihydro-2H-1,3-benzoxazine 300 3 hexadecyl 3,4 dihydro-2H-1,3-benzoxa zine 1450 6 methyl-3-hexadecyl 3,4 dihydro-2H-1,3-

benzoxazine -3 1650 3,4 dihydro-3-octadecyl-2H 1,3-benzoxazine 1350 6-(1,1-di methylpropyl) 3 cyclohexyl-3,4-dihydro-ZI-I-lfi-benzoxazine 950 6 nonyl-3-cycloheXy-l 3,4 dihydro-2H-1,3-

benzoxazine 1200 6-dodecyl-3-cyclohexyl 3,4 dihydro-2H-1,3-

benzoxazine 1425 EXAMPLE 2 The procedure of Example 1 was repeated with another similar soil sample with the following results,

, Table II S-2I-I-1,3-BO compound: MR in millibars Control 3717 6 methyl 3 cyclohexyl 3,4 dihydro-2H- 1,3 benzoxazine 1550 6 isopropyl 3 -cyclohexyl 3,4 dihydro-2H- 7 1,3 -benzoxazine 1900 6,8 disec butyl 3 cyclohexyl 3,4 dihydro 2H 1,3 benzoxazine 1875 6 pentyl 3 cyclohexyl 3,4 dihydro 2H- 1,3 benzoxazine 2550 6 (1,1 dimethylbutyl) 3 cyclohexyl 3,4-

dihydro 2H 1,3 -benzoxazine 1850 6 sec hexyl 3 cyclohexyl 3,4 dihydro- 2H 1,3 benzoxazine 1733 6 (1 ethyl 1 methylpropyl) 3 cyclohexyl 3,4 dihydro 2H 1,3 benzoxazine 1938 6 (1 ethyl 1 methylbutyl) 3 cyclo- I hexyl 3,4 dihydro- 2H 1,3 benzoxazure 6 (l ethyl 1 methylpentyl) 3 cyclm hexyl 3,4 dihydro 2H 1,3 benzoxazine 1450 p 6 sec butyl 3 cyclohexyl 3,4 dihydro- 2H 1,3 benzoxazine 1750 6 (1 methylbutyl) 3 cyclohexyl 3,4-

dihydro 2H 1,3 benzoxazine 2425 D EXAMPLE 3 The procedure of Example 1 was repeated with another similar soil sample with the following results.

Table III S-2H-1,3-BO compound: MR in millibars Control 2283 6 -te1't butyl 3,4 dihydro 3 methyl 2H- 1,3 benzoxazine 6 tert butyl 3 butyl 3,4 dihydro 2H- 1,3 benzoxazine 625 6 tert butyl 3 allyl 3,4 dihydro 2H- 1,3 benzoxazine 0 6 tert butyl 3,4 dihydro 3 octyl 2H- 1,3 benzoxazine 375 6 tert butyl 3 dodecyl 3,4 dihydro- 2H 1,3 benzoxazine 1225 EXAMPLE 4 The procedure of Example 1 was repeated with another similar soil sample with the following results.

Table IV S- 2Hl,3-BO compound: MR in millibars Control 3250 3,6 dimethyl 3,4 dihydro 2H 1,3-benzoxazine 2700 3,4 dihydro 3 propyl 2H 1,3 benzoxazine 1975 6 (1,1 dimethylpropyl) 3 sec butyl- 3,4 dihydro 2H 1,3 benzoxazine 0 6 (1,1 dimethylpropyl) 3,4 dihydro 3- t pentyl 2H 1,3 benzoxazine 0 3 hexyl 3,4 dihydro 2H 1,3 benzoxazine 2000 6 methyl 3 hexyl 3,4 dihydro 2H- 1,3 benzoxazine 325 6 (1,1 dimethylpropyl) 3 hexyl 3,4-

dihydro 2H 1,3 benzoxazine 0 6 (1,1 dimethylpropyl) 3 (1,3 dimethylbutyl) 3,4 dihydro 2H 1,3 benzoxazine 0 6 methyl 3 (2 cyclohexylcyclohexyD- 3,4 dihydro 2H 1,3 benzoxazine 2600 6 tert butyl 3 (2 cyclohexylcyclohexyl)- 3,4 dihydro 2H 1,3 benzoxazine 2200 6 (1,1 dimethylpropyl) 3 (2 cyclohexylcyclohexyl) 3,4 dihydro 2H 1,3 benzoxazine 1925 6 methyl 3 (4 cyclohexylcycloheXyD- 3,4 dihydro 2H 1,3 benzoxazine 2400 EXAMPLE .5

The procedure of Example 1 was repeated with another similar soil sample with the following results.

The procedure of Example 1 was repeated with an other similar soil sample with the following results.

Table VI S-2H-1,3-BO compound: MR in millibars Control 2700 6 ethyl 3,4 dihydro -3 methyl 2H 1,3-

benzoxazine 1700 6 isopropyl 3,4 dihydro 3 methyl 2H- 1,3 benzoxazine 1250 6 tert butyl 3,4 dihydro 3 isopropyl- 2H 1,3 benzoxazine 1500 8 tert butyl 3 -cyclohexyl 3,4 dihydro- 2H 1,3 benzoxazine 1800 6 tert butyl 3,4 dihydro 3 (2 methylcyclohexyl) 2H 1,3 benzoxazine 1900 6 cyclohexyl 3,4 dihydro 3 propyl 2H- 1,3 benzoxazine 1200 6 cyclohexyl 3 hexyl 3,4 dihydro 2H- 1,3 benzoxazine 1150 6 cyclohexyl 3,4 dihydro 3 octyl 2H- 1,3 benzoxazine 1400 EXAMPLE 7 Several g. samples of a finely ground, air-dried, slightly acid, clay loam soil were brought up to a moisture content of about 17%. Various weights of S-2H- 1,3-BO compound, as indicated'(5 mg., 10 mg., 50 mg., 100 mg), were dissolved in 10-ml. aliquots of acetone and sprayed with intimate mixing onto separate samples of soil.

The soil was then evaluated by MR determinations, as given in following Table VII.

Table VII S2H1,3 BO Compound P.p.rn. MR in in soil millibars Control... 5, 800 50 3, 800 6-tert-butyl-3,4-dihydro-3-methyl-2H-1,3-benz- 100 3, 400 oxaz'me 1 8 EXAMPLE 8 VIII-B.

Table VIII-A SOILS USED Mechanical ..Moisture analysis Percent content at Soil O.M. pH treatment in percent Sand Silt Clay 1 Organic matter. Table VIII-B MR in millibars Soil S-2H-1,3-BO Control Compound 1 1 6-tert-butyl-3,4-dihydro-3-methyl-2H-l,3-benz0xazine.

What is claimed is:

1. The method of treatment of clays and clay-containing soils containing at least weight percent clay, soil basis, by admixing therewith a dispersion, in an inert dispersion medium, of a compound having the formula:

Ra I

N-Ra in which R is one of alkyl containing 1 to 18 carbon atoms and cycloalkyl containing 6 to 12 carbon atoms; R is one of H, alkyl containing 1 to 12 carbon atoms and cyclohexyl; and R is one of H, alkyl containing 1 to 12 carbon atoms and cyclohexyl in amount sufiicient to provide at least 0.0025 weight percent of said compound, dry clay basis.

2. A composition of a clay material of the group consisting of clays and clay-containing soils having at least 5 weight percent clay, dry soil basis, and containing in admixture therewith at least 0.0025 weight percent, day basis, of a compound having the formula:

in which R is one of alkyl containing 1 to 18 carbon atoms and cycloalkyl containing 6 to 12 carbon atoms; R is one of H, alkyl containing 1 to 12 carbon atoms and cyclohexyl; and R is one of H, alkyl containing 1 to 12 carbon atoms and cyclohexyl.

3. The composition of claim 2 wherein the compound is 6-cyclohexyl-3,4-dihydro-3-(3,5,5-trimethylhexyl)-2H- 1,3-benzoxazine.

4. The composition of claim 2 wherein the compound is 6-cyclohexyl-3-dodecyl-3,4-dihydro 2H-1,3-benzoxazine.

5. The composition of claim 2 wherein the compound is 3,6-didodecyl-3,4-dihydro-2H-1,3-benzoxazine.

6. The composition of claim 2 wherein the compound is 6-(1,1-dimethylpropyl)-3-cyclohexyl 3,4 dihydr0-2H- 1,3-benzoxazine.

7. The composition of claim 2 wherein the compound is 6- nonyl-3-cyclohexyl-3,4-dihydro-2H-l,3-benzoxazine.

8. The composition of claim 2 wherein the compound is 6-methyl-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine.

9. The composition of claim 2 wherein the compound is 6,8 di-sec-butyl-3-cyclohexyl-3,4-dihydro-2H-l,3-benzoxazine.

10. The composition of claim 2 wherein the compound is 6-( 1,1-dimethylbutyl)-3-cyclohexyl-3,4-dihydro-2H-1,3- benzoxazine.

11. The composition of claim 2 wherein the compound is 6 sec-hexyl-3-cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine.

12. The composition of claim 2 wherein the compound 8 is 6-( l-ethyl-l-methylpentyl) -3-cyclohexyl 3,4 dihyclro- 2H-l,3-benzoxazine.

13. The composition of claim 2 wherein the compound is 6-sec-butyl-3-cyclohexyl 3,4 dihydro-2H-1,3-benzoxazine.

14. The composition of claim 2 wherein the compound is 6-tert-butyl-3 ,4-dihydro-3-methyl-2H- l ,3-benzoxazine.

15. The composition of claim 2 wherein the compound is 6-tert-butyl-3-butyl-3,4-dihydro-2H-1,3-benzoxazine.

116. The composition of claim 2 wherein the compound is 6-tert-butyl-3-a1lyl3,4-dihydro-2H-l;3-benzoxazine.

17. The composition of claim 2 wherein the compound is 6-tent-butyl-3,4-dihydro-3 ootyl-2i-L1,3-benzoxazine.

18. The composition of claim 2 wherein the compound is 6 l, l-dimethylpropyl) -3-sec-butyl-3,4-dihydro-2H- l ,3- benzoxazine.

19. The composition of claim 2 wherein the compound is 6 (l,l-dimethylpropyl)-3,4-dihydro-3 pentyl-2H-1,3-

benzoxazine.

20. The composition of claim 2 wherein the compound is 6-methyl-3-heXyl-3,4-dihydro'2I-l-1,3 benzoxazine.

21. The composition of claim 2 wherein the compound is 6 (1,1-dimethylpnopyl)-3-hexyl3,4-dihydro-2H-l,3 benzoxaziine.

22. The composition of 2 wherein the compound is 6 (1,1-d imethy1propyl)-3-(1,3-dimethylbutyl)-3,4:dihydro-ZH-LS-benzoxazine.

23. The composition of claim 2 wherein the compound is 6 (1,-1 dimethylpropyD-3-(-2-cyclohexylcy-clohexyl) -3, 4-dihydro 2I-I-l,3benzoxazine.

24. The com-position of claim 2 wherein the compound is 6 sec-butyl-3,4-dihydro-3-metthyl-2H-1,3-benzoxazine.

25. The composition of claim 2 wherein the compound is .6 (l,l,3,3-tetramethylbutyl)-3,4-dihydro-3=methyl- .2H-1,34benzoxazine.

26. The composition of claim 2 wherein the compound is 6-sec-flouty1-3,4-dihydro-3-isopropy1-2H-l,3-benzoxazine.

27. t The composition of claim 2 wherein the compound is 6 isopropyl 3,4-dihydro-3-methy1-2H-1,3-benzoxazine.

28. The composition of claim 2 wherein the compound is p 6 cycloheXyl-3,4-dihydro-3-propyl-2H-1,3-benzoxazine.

29. The composition of claim 2 wherein the compound is 6 cyclohexyl 3-hexyl-3,4-dihydro-2H-1,3-benzoxazine.

References Cited in the file of this patent UNITED STATES PATENTS 2,768,089 Erickson Oct. 23, 1956 2,806,031 Risterink Sept. 10, 1957 2,811,523 Riste-rink -2 Oct. 29, 1951] 2,831,779 Erickson Apr. 22, 1958 OTHER REFERENCES Lambe et al.: Chem. Eng. News, vol. 32, No. 6, Feb. 8, 1954, pages 488-492.

Martin: Soil Science of America Proceedings, vol. 117, No. 1-, January 1953, pages 1-9. 

2. A COMPOSITION OF A CLAY MATERIAL OF THE GROUP CONSISTING OF CLAYS AND CLAY-CONTAINING SOILS HAVING AT LEAST 5 WEIGHT PERCENT CLAY, DRY SOIL BASIS, AND CONTAINING IN ADMIXTURE THEREWITH AT LEAST 0.0025 WEIGHT PERCENT, CLAY BASIS, OF A COMPOUND HAVING THE FORMULA: 